Vintage photo from daguerreotype of President Abraham Lincoln in 1863. Abraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th President of the United States. He successfully led the country through its greatest internal crisis, the American Civil War, preserving the Union and ending slavery. As the war was drawing to a close, Lincoln became the first American president to be assassinated. Before his election in 1860 as the first Republican president, Lincoln had been a country lawyer, an Illinois state legislator, a member of the United States House of Representatives, and twice an unsuccessful candidate for election to the U.S. Senate. As an outspoken opponent of the expansion of slavery in the United States, [1] [2] Lincoln won the Republican Party nomination in 1860 and was elected president later that year. The daguerreotype is a direct-positive process, creating a highly detailed image on a sheet of copper plated with a thin coat of silver without the use of a negative. The process required great care. The silver-plated copper plate had first to be cleaned and polished until the surface looked like a mirror. Next, the plate was sensitized in a closed box over iodine until it took on a yellow-rose appearance. The plate, held in a lightproof holder, was then transferred to the camera. After exposure to light, the plate was developed over hot mercury until an image appeared. To fix the image, the plate was immersed in a solution of sodium thiosulfate or salt and then toned with gold chloride. Exposure times for the earliest daguerreotypes ranged from three to fifteen minutes, making the process nearly impractical for portraiture. Modifications to the sensitization process coupled with the improvement of photographic lenses soon reduced the exposure time to less than a minute. Although daguerreotypes are unique images, they could be copied by redaguerreotyping the original. Copies were also produced by lithography or engraving. Portraits based upon daguerreotypes appeared in popular periodicals and in books.